1. Field
Apparatuses and methods consistent with exemplary embodiments relate to a display apparatus, a power supply apparatus and a power supply method thereof, and more particularly, to a display apparatus, a power supply apparatus and a power supply method thereof which include a discharging circuit that removes a remaining voltage from a power supply unit when alternating current (AC) power supply is cut off and does not consume power in a standby mode.
2. Description of the Related Art
A display apparatus such as a television (TV) includes a power supply unit which receives and converts AC commercial power into operating power at a level necessary for elements receiving such power and supplies the converted operating power to the elements.
FIG. 1A illustrates an AC power input circuit diagram of a power supply unit of a related TV. As shown therein, the related art AC power input circuit includes a discharging resistor 1 and a noise-reducing AC filter 3. The AC filter includes a capacitor and an inductor, and when a TV operates generally, a voltage equivalent to an AC input voltage is charged to the capacitor. If a user unplugs the display apparatus, the discharging resistor 1 discharges a voltage charged to the capacitor (hereinafter, to be called “remaining voltage”) since the remaining voltage may cause an electric shock.
FIGS. 1B and 1C illustrate a function of the discharging resistor 1 included in the related art AC power input circuit diagram of FIG. 1A. As shown in FIG. 1B, if the discharging resistor 1 is not provided in the AC power input circuit, a natural discharge of the remaining voltage from the capacitor requires a long discharge time and causes an electric shock after the input of the AC power is cut off. As shown therein, 115V still remains even after two seconds has elapsed.
As shown in FIG. 1C, if the discharging resistor is provided in the AC power input circuit, the remaining voltage is discharged in a very short time of 0.85 seconds after the input of the AC power is cut off. In that respect, the discharging resistor should be provided in the AC power input circuit.
However, as in the related art AC power input circuit diagram in FIG. 1A, the discharging resistor 1 receives a voltage which is the same as the AC input voltage and consumes power unnecessarily when the AC input voltage is applied to the AC input circuit, because the discharging resistor is connected in parallel to the AC input voltage. The power consumed by the discharging resistor 1 accounts for a considerable amount of the power consumed in a standby mode, which is a waste of energy.